The present invention relates to a printing system including a plurality of image forming apparatuses, a sheet supply supporting method of supporting to make it possible to supply sheets by one bundle or a box as a unit of supply into sheet trays of image forming apparatuses and a control program to judge whether it is possible to supply sheets by one bundle or a box as a unit of supply. Here, in the present specification, a sheet-shape recording material to form an image thereon, such as a copy paper, a recording sheet and the like is referred to as “sheet”.
Printing apparatuses (hereafter, referred to as image forming apparatuses), such as printers and digital composite machines have been widely used. Such an image forming apparatus conducts processes of forming an image based on a print job and transfers the image onto a sheet stored in a sheet tray. However, if there is no sheet in the tray, the print job is interrupted. Therefore, the sheet administration such as, purchase, storage and supply is very important for the operation of the image forming apparatus.
With regard to the sheet administration in an image forming apparatus, a generally known technique detects a quantity of remaining sheets in a sheet tray and notifies the necessity of sheet supply if the quantity of remaining sheets becomes equal to or less than a threshold value. For example, Japanese Patent Unexamined Publication No. 5-301430 discloses a technique to urge an operator to conduct sheet supply by indication or alarm in the case that the quantity of remaining sheets is little at the time of starting a print operation or at the time that a print operation is stopped by occurrence of errors.
Here, sheets used in image forming apparatuses are purchased on a packaged condition that hundreds of sheets are made in one bundle and then one or plural bundles of sheets are stored in a box. When a package is opened and some sheets of one bundle of sheets are supplied to a sheet tray, the remaining sheets are preserved in many cases on the condition that they are carelessly piled up on a shelf. In this case, there is a problem that the remaining sheets become dirty or are partially bent and then become unable to be used. In addition, there is another problem that the remaining sheets spoil a fine view.
In order to avoid the above problems, it is desired to supply sheets by one or plural bundles (for example, one box) as a unit of supply. However, since the size of a sheet tray is generally set so as to store one bundle or plural bundles of sheets exactly, if sheet supply is conducted on the condition that sheets remain in a sheet tray, some sheets of a bundle of sheets cannot be stored in the sheet tray. As a result, it becomes impossible to avoid the above problems.
Therefore, with the conventional technique, since sheet supply can be conducted before all of sheets in a sheet tray have been used, from the viewpoint for an apparatus to conduct a print job, the interruption of the print job due to no sheet can be avoided. However, from the viewpoint for an operator to conduct sheet supply, it becomes necessary for the operator to administrate sheets remaining after the sheet supply. As mentioned above, the remaining sheets become dirty or are partially bent and then become unable to be used. Therefore, there are problems to cause loss in cost and resource and to spoil a fine view of a sheet storage place.